Nagoya University · 물리·천문학
마사히로 호리타 교수의 연구실은 nitride 계 반도체, 특히 GaN 및 AlN의 고질적 에피택시얼 성장과 결함 물리학을 중심으로 연구를 진행하고 있습니다. 특히 p형 도핑된 GaN의 전하 수송 특성, Fe 불순물에 의한 전자 트랩 메커니즘, 그리고 전자빔 조사에 의한 점결함 생성 메커니즘을 깊이 있게 분석하고 있습니다. 비정방향(비정렬) 표면에서의 고순도 AlN 성장과 결함 제어 기술도 핵심 연구 분야입니다. 이는 고성능 전자소자 및 파owe레일 전자소자 응용을 위한 기초 소재 기술 개발을 목표로 합니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Mg-doped p-type gallium nitride (GaN) layers with doping concentrations in the range from 6.5 × 1016 cm−3 (lightly doped) to 3.8 × 1019 cm−3 (heavily doped) were investigated by Hall-effect measurement for the analysis of hole concentration and mobility. p-GaN was homoepitaxially grown on a GaN free-standing substrate by metalorganic vapor-phase epitaxy. The threading dislocation density of p-GaN was 4 × 106 cm−2 measured by cathodoluminescence mapping. Hall-effect measurements of p-GaN were car
The origin of E3 electron traps at EC –0.58 eV in GaN was investigated using Si-doped n-type GaN layers grown on freestanding GaN substrates using MOVPE. These layers contained impurity Fe at various concentrations depending on the growth conditions and the position within the wafer. Twenty E3 concentrations (NT,E3) determined by deep-level transient spectroscopy were plotted against the corresponding Fe concentrations ([Fe]) obtained from secondary ion mass spectrometry. A correlation was evide
Growth of very high-quality nonpolar (112¯0) a-plane face 4H-AlN on 4H-SiC (112¯0) substrate was investigated. Nonpolar 4H-AlN (112¯0) was isopolytypically grown on 4H-SiC (112¯0) substrate by molecular-beam epitaxy. A reduction of defects such as stacking faults and threading dislocations was achieved by keeping the growing surface flat. To this end, the SiC substrate was HCl gas etched and the V/III ratio was optimized for AlN growth. A full width at half maximum of symmetrical x-ray diffracti
Energy levels due to intrinsic point defects are identified by deep-level transient spectroscopy (DLTS). Electron-beam (EB) irradiation created nitrogen vacancies (VN) and nitrogen interstitials (NI) in n-type GaN layers grown via metalorganic vapor phase epitaxy on freestanding GaN substrates, where the irradiation energies were selected to be within 100–401 keV to displace only nitrogen atoms in GaN. Two electron traps, EE1 (0.13 eV) and EE2 (0.98 eV), were observed in the DLTS spectra. The pr
